On sol 47, ending at 12:36 p.m. February 20, 2004 PST, engineers woke Spirit up to the song "Dig Down Deep," by Hot Soup, and that's exactly what Spirit proceeded to do. The two-hour operation performed by Spirit's left front wheel resulted in a trench 7-8 centimeters deep (2.8 to 3.1 inches) that uncovers fresh soil and possibly ancient information.
Spirit dug this trench at "Laguna Hollow" the same way that Opportunity dug its 9-10 centimeter (3.5 to 3.9 inch) trench at Meridiani. However, because the ground at this location is harder, Spirit had to dig for twice as long as Opportunity - going back and forth over the surface 11 times instead of 6.
After the trench was completed, Spirit backed up one meter, or more than a yard, and analyzed the area with the miniature thermal emission spectrometer before driving forward 0.4 meters (15.7 inches) and imaging the excavation site with the panoramic camera. A final move forward of another 0.4 meters allowed Spirit to take front hazard avoidance camera images of the arm work volume which was then centered on the trench.
After stowing the arm, the rover did a series of miniature thermal emission spectrometer observations of several nearby rocks, "Buffalo," "Cherry," "Cotton," and "Jiminy Cricket," and a combined miniature thermal emission spectrometer and panoramic camera observation of "Beacon." Spirit also took panoramic camera images of its deck to observe dust accumulation on the instrumented solar cells and on the miniature thermal emission spectrometer calibration target.
Spirit then took a siesta from 2 p.m. to 3:45 p.m. Mars Local Solar time and woke up for some more panoramic camera and miniature thermal emission spectrometer observations of "Beacon," and miniature thermal emission spectrometer ground and sky stares. All activities up through the afternoon pass by the Mars Odyssey orbiter were completed successfully.
OPPORTUNITY UPDATE: Enter the Rock Abrasion Tool - sol 26, Feb 20, 2004
On sol 26, which ended at 12:18 a.m. Friday, February 19, PST, Opportunity successfully obtained one final Moessbauer spectrometer reading of the trench, stowed the rover arm, and drove 15 meters (50 feet) to the "El Capitan" area. The drive was Opportunity's longest yet and required the vehicle and planners to skirt the trench and avoid the lander.
The plan for sol 27, which will end at 12:57 a.m. Saturday, PST, is to first "supersize" the measurements of the "El Capitan" area with the panoramic camera, miniature thermal emission spectrometer, and microscopic imager. The mineralogy and geology teams have requested a minimum of three hours worth of "super resolution" and "super spectral" observations for the science instruments to get the most comprehensive coverage of this interesting site, which has varying textures and layers of dirt and rock.
After a short siesta in the early afternoon, Opportunity will drive 30 centimeters (12 inches) to sneak a bit closer to the rocks in "El Capitan" to get ready for the rock abrasion tool to do its work. After the drive, the Opportunity team plans to take a picture of the martian sky with the panoramic camera and miniature thermal emission spectrometer. If time permits, Opportunity will attempt to aim its cameras toward the heat shield in the far distance.
Over the weekend, Opportunity plans to find the perfect spot to use the abrasion tool and set it loose to grind away on "El Capitan," which will be the first use of the rock abrasion tool by Opportunity.